Microfluidic BBB-on-a-chip models (μBBB) aim to recapitulate the organotypic features of the human BBB with great potential to model CNS diseases and advance CNS therapeutics. Nevertheless, their predictive capacity for drug uptake into the brain remains uncertain due to limited evaluation with only a small number of model drugs. Here, the in vivo brain uptake of a panel of nine radiolabeled compounds is evaluated in Swiss-outbred mice following a single intravenously administered dose and compared against results from the microfluidic μBBB platform and the conventional Transwell BBB model.
View Article and Find Full Text PDFIn order to effectively adjust reservoir heterogeneity and further exploit the remaining oil, a new type of low-viscosity gel was prepared by adding a regulating agent, retarder, and reinforcing agent on the basis of a polymer + Cr crosslinking system. The new gel has the advantages of low initial viscosity, a slow gel formation rate, and high strength after gel formation. The effectiveness of the gel was verified through three-layer core displacement experiments, and the injection scheme was optimized by changing the slug combination of the polymer and the gel.
View Article and Find Full Text PDFBackground: Poor sleep quality has been linked to depression in older adults, but results of the association between daytime napping and depression remains limited and conflicting. Moreover, whether the association of daytime napping with depression varies by nighttime sleep quality is unclear. Hence, we examined the associations of daytime napping and nighttime sleep quality with depressive symptoms in older Chinese.
View Article and Find Full Text PDFOvercoming the blood-brain barrier (BBB) remains a significant challenge with regard to drug delivery to the brain. By incorporating targeting ligands, and by carefully adjusting particle sizes, nanocarriers can be customized to improve drug delivery. Among these targeting ligands, transferrin stands out due to the high expression level of its receptor (i.
View Article and Find Full Text PDFBackground And Aims: Magnifying image-enhanced endoscopy (MIEE) is an advanced endoscopy with image enhancement and magnification used in preoperative examination. However, its impact on the detection rate is unknown.
Methods: We conducted an open-label, randomized, parallel (1:1:1), controlled trial in 6 hospitals in China.
This study examined the association between parity and incident type 2 diabetes in older Chinese women and estimated the mediation effect of adiposity indicators. A total of 11,473 women without diabetes at baseline from 2003 to 2008 were followed up until 2012. We used Cox proportional hazards regression to assess the association between parity and incident type 2 diabetes, and mediation analysis to estimate the mediation effect of adiposity indicators.
View Article and Find Full Text PDFOlder people have higher amounts of sodium accumulation in skeletal muscles than younger people, indicating the possible role of salt intake on muscular and physical function. This large population-based cross-sectional study examined the association of salt intake with muscle strength and physical performance in 4867 participants with an average age of 60.4 (standard deviation = 7.
View Article and Find Full Text PDFHaving a later age at menopause is associated with having a higher blood pressure (BP) value, but the mediation pathways remain unclear. We quantitatively examined the mediation effects of various obesity indicators using baseline data from phase 4 of the Guangzhou Biobank Cohort Study. The product of coefficients approach and bootstrapping procedures were used to assess the mediation effects of body mass index (BMI), waist circumference (WC), waist-to-hip ratio (WHR) and waist-to-height ratio (WHtR) on the association between age at menopause and BP values.
View Article and Find Full Text PDFStudy Objective: Evidence regarding the association of short sleep duration and napping with stroke remains limited and controversial. We examined the association of sleep duration and napping with risk of stroke mortality in an older Chinese cohort.
Methods: Sleep duration and daytime napping were assessed by face-to-face interview during 2003-2008.
Background: Lower hand grip strength has been linked to cognitive impairment, but studies in older Chinese are limited. We examined the association of hand grip strength with cognitive function in a large sample of older Chinese. Methods: 6806 participants aged 50+ years from the Guangzhou Biobank Cohort Study (GBCS) were included.
View Article and Find Full Text PDFThe long-term effects of a low-carbohydrate diet (LCD) on mortality, accounting for the quality and source of the carbohydrate, are unclear. Hence, we examined the associations of LCDs with all-cause and cause-specific mortality in a prospective cohort study. A total of 20,206 participants (13.
View Article and Find Full Text PDFBackground: Chronic inflammatory diseases are linked to an increased risk of stroke events. The white blood cell (WBC) count is a common marker of the inflammatory response. However, it is unclear whether the WBC count, its subpopulations and their dynamic changes are related to the risk of fatal stroke in relatively healthy elderly population.
View Article and Find Full Text PDFBMC Genomics
September 2021
Objective: From genome-wide association studies, brain-derived neurotrophic factor (BDNF) locus on chromosome 11 was the only SNP associated with both smoking and body mass index (BMI) in European, African and Asian population. This study aims to explore the unique genetic predisposition to obesity in former smokers by examining the effects of BDNF on BMI and waist circumference (WC).
Methods: The study design is case-control study with a cohort validation in supplementary.
Objective: To examine the associations of natural menopausal age with cardiovascular disease risk factors and whether the associations varied by parity in older Chinese women.
Methods: Information of demographic characteristics, lifestyles, and reproductive factors was collected by face-to-face interview. Framingham Risk Score was used as an indicator of cardiovascular disease risk, with a score ≥ 10% considered as high cardiovascular disease risk (vs low, dichotomous).
Neurological disorders such as Alzheimer's disease, stroke, and brain cancers are difficult to treat with current drugs as their delivery efficacy to the brain is severely hampered by the presence of the blood-brain barrier (BBB). Drug delivery systems have been extensively explored in recent decades aiming to circumvent this barrier. In particular, polymeric nanoparticles have shown enormous potentials owing to their unique properties, such as high tunability, ease of synthesis, and control over drug release profile.
View Article and Find Full Text PDFBackground: The role of smoking in nasopharyngeal carcinoma (NPC) remains uncertain, especially in endemic regions. We conducted an individual participant data (IPD) meta-analysis of prospective cohort studies to investigate the associations between smoking exposure and risk of NPC.
Methods: We obtained individual participant data of 334 935 male participants from six eligible population-based cohorts in NPC-endemic regions, including two each in Guangzhou and Taiwan, and one each in Hong Kong and Singapore.
Background: Physical activity (PA) is generally encouraged. Studies from developed countries in the West have shown that maintenance of adequate PA or increasing PA are associated with lower mortality risk. It is unclear whether these associations apply to an older Chinese population.
View Article and Find Full Text PDFObjectives: To examine whether hepatitis B surface antigen (HBsAg) seropositivity and hepatitis B surface antibody (HBsAb) seropositivity were associated with the presence of diabetes in two population-based studies in southern China, the Guangzhou Biobank Cohort Study (GBCS) and the Major Infectious Disease Prevention and Control (MIDPC) study.
Design: A cross-sectional study.
Setting: The GBCS was conducted among a community social and welfare organisation with branches in all 10 districts of Guangzhou.
The development of dominant seepage channels after polymer flooding makes it more difficult to effectively exploit reservoirs, and gel plugging technology is an effective method to solve this problem. However, conventional gels experience problems such as high initial viscosity and they easily contaminate the medium- and low-permeability layers. Therefore, a low-initial-viscosity gel plugging agent is proposed in this paper.
View Article and Find Full Text PDFTo improve the oil displacement effect of polymer solutions in heterogeneous oil layers and increase the energy utilization rate, Daqing Oilfield proposes a partial pressure tool to control the polymer solution injection amount in high-permeability oil layers and increase the injection amount in low-permeability oil layers to enhance the total oil recovery. To study the effect of the partial pressure tool on enhancing oil recovery and the action mechanism of the tool on polymer molecules in high-permeability reservoirs, core displacement experiments were performed to study the effects of various factors on oil recovery. Microscopic experiments were then carried out to study the differences in molecular morphology and molecular coil size of the microscopic polymer solution before and after the action of the partial pressure tool.
View Article and Find Full Text PDFClin Endocrinol (Oxf)
December 2019
Objective: In this study, a genetic risk score (GRS) for the body mass index (BMI) tested and built using a large sample of Chinese individuals aged at least 50 years in southern China. We collected information regarding the participants' weights at 20 years of age and middle age and tested the BMI-GRS effect modes.
Methods: This study involved a prospective study design.
To clarify the causal role of age at menarche in depressive symptoms we conducted a Mendelian randomization study using a large Southern Chinese cohort (n = 12,233). A genetic allele score was derived using stepwise regression with cross validation. Older age at menarche was not associated with geriatric depression scale score.
View Article and Find Full Text PDFObservational studies show earlier age at menarche associated with higher risk of cardiovascular disease although these studies could be confounded by childhood obesity or childhood socioeconomic position. We tested the hypothesis that earlier age at menarche is associated with poorer cardiovascular risk factors using a Mendelian randomization design. We conducted a Mendelian randomization study in a large Southern Chinese cohort, the Guangzhou Biobank Cohort Study (n=12,279), to clarify the causal role of menarche in cardiovascular disease risk factors including blood pressure, lipids, fasting glucose, adiposity and type 2 diabetes.
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